I don't know what your OE's are "made" of, but likely a dark egg layer (marans/welsummer) and a blue or green egger (EE or Ameraucana).
To answer your first question, will the pullets from your olive eggs also produce olive eggs? Maybe. That depends a lot on what daddy was. Those with pea combs will have retained at least 1 blue gene, and will at least give you green eggs. If there are enough other dark brown genes between the parents, they will tend towards olive.
If you have an OE roo (with pea comb), and you cross him to a standard brown egg layer (BO, Sexlink...) about half of the chicks will get the blue gene, and will lay green to olive eggs. There's no guarantee how dark they will be, since normal brown eggs don't have the extra dark coatings that ultimately give the olive appearance to the egg. Crossing back to a Marans or a Welsummer and raising the pea combed chicks would be the best way to get darker and darker olive eggs.
It should be possible to create a pure breeding line of olive eggers, but it's tricky to tell which birds are carrying one blue gene, and which are carrying two, as they would all lay the same colored egg, or have pea combs in the case of roos. Ideally all birds in the flock would have 2 copies of the gene so that it would always be given to each generation. Even after the blue genes are stabilized you would probably have to continually select for the darkest eggs, like the Marans breeders do.
I have a cute little Cuckoo Marans over Blue Ameraucana pullet. I can't wait until she's big enough to lay! Good luck!
Bailey
